For example Patent Literature 1 discloses a conventional input device. The input device (an operational user-interface device) disclosed by Patent Literature 1 includes a remote touchpad unit for a user to perform a touch operation, a display unit to display a multimedia system of various modes according to three-dimensional signals received from the remote touchpad unit, and a controller to control the operation of the multimedia system according to the three-dimensional signals of the remote touchpad unit.
In the input device disclosed by Patent Literature 1, when the position of a user's finger is located in a range of a first height from the surface of the remote touchpad unit, the position of the finger (pointer) is displayed on the display unit to enable a detailed operation through the movement of the pointer and the changeover of a menu.
When the position of the user's finger is located in the range from the first height to a second height, switching between a first mode and a second mode is enabled by a wipe pass gesture, and movement among a home, a main, and a sub screen is also enabled.
When the position of the user's finger is located in the range from the second height to a third height, switching to an operation standby screen is enabled in a radio main screen.
Furthermore, in Patent Literature 1, an illumination part is provided in a remote touchpad unit or a display unit for example. When a finger is in a height exceeding 7 cm from the surface of the remote touchpad unit, the illumination part is displayed in the state turned off. As the finger approaches the remote touchpad unit, the hue of the illumination part becomes deep gradually. When the finger is in contact with the remote touchpad unit, the illumination part is displayed by a hue different from the above-described hue. Accordingly, it is possible for a user to recognize easily how the finger has approached the remote touchpad unit.